Lifting mechanism



Jan- 12, 1932. l. v. K. HOTT LIFTING MECHANISM Filed Aug. l, 1927 2 Sheets-Sheet l Jan. 12, 1932. v. K. HOTT LIFTING MECHANISM Filed Aug. l. 1927 2 Sheebs-Sheell 2 TTUPNE Y Patented Jan. 12, 1w932 UNITED STATES PATENT OFFICE ION V. .K. HOTT, VOli DAYTON, OHIO, .ALSSIGNOR T THE TOYGE-CRIDLANDv COMPANY, OF DAYTON, OHIO, A. CORPORATION OF .OHIO

VLIFTING- MECHANSM Application :filed August 1, 1927. Serial No. 209,711.

rlhis invention relates to lifting Imechanisms and more particularly .to a lifting ack designed for Aheavy duty. .Lifting jacks are usually rhand operated and to this end .are provided with an operating lever. When operating .under :a heavy load it requires the services of two nien -to actuate the ack .and the voperation is slow. It :is therefore desirable .that lthe ljack Abe provided with power y, operated means for actuating the same, thus eliniinatingithe services of one man and securing a much .more rapid operation.

@ne object :of the present invention is to provide a lifting ack :wit-han .air zmotor perigf. manently attached thereto and adapted to be connected bya iiexib'lezcon'duit with anysuitable source .of Vsupply Aof air under pressure, such as 'is usually found in .shops and other locations inwhich yheavy .duty jacks are used. y fr further :objectief the'i-nvention is :to provide aself-.lowering jack with an air motorso connected Atherewith vthat it will operate both to impart liftingmovement -to the liftingie'lep nient and te :retardthe lowering movementof i; the liftingfelement.

:i further ob; ect o'f the invention is to proing element when the latter reaches the -limit of :its .mov-ement.

furthercbj ect of the invention is to provi de .meanswhereby such a -jaclrlmaybe easily transported ffroniplace to place. 25 @therfobjects ofthe invention will'appear the device isrdescribed indetail. in the 4accompanyingdrawings Fig. 1 is a vertical sectional view taken centrally through a jack embodying my invention, showing the motor fin elevation; Fig. 2 is a transverse section'taken on the line 2 2 of 1; Fig. 3 is a section taken on the line of Fig, 1; Fig. 4 is a sectional view taken on the line of Fig'. 1, showing' the driving gearing in elevation; Fig. 5 is a trans.

8 is a detail view, partly broken away, of the cam shaft.

In these drawings I have illustrated one embodiment of `my invention and have shown the same as applied to a screw ack of a well known type but it will be understood that this particular embodiment has been chosen for the purpose of illustration only and that the invention ymay be applied to aclrs of various kinds and that the manner of mounting the motor, connecting the same with a lifting element and ycontrolling its operation, may take various iforms.

The jack there illustrated comprises an upright standard consisting of a base 10and a vertical housing 11 rigidly secured to said base, extending upwardly therefrom and having at its upper end a bearing 12. Slidably mounted in the bearing 12, for vertical movement in the housing, is a ram or hollow lifting element 13 having at its upper end a cap or load engaging member 14. A nut 15 is mounted in the lower end of the lifting element or ram and threaded in this nut is a lifting screw 16 which is rotatably mounted on the base 10. In the present instance, a ball bearing 17 supports'the screw on the base. The nut 15 has a flange 18 which projects beyond the side of the ram and is arranged to engage a shoulder or stop 19 provided on 3 the inner wall of the housing near the upper endthereof, and .thus limit the upward movement of the lifting element or ram. Rigidly secured to the lower portion of the screw is a beveled gear 2O which rests upon the ball 3;; bearing 17 and which meshes with a second beveled gear 21, the beveled gears and the screw constituting the actuating device for the lifting element. The housing is proyided at its lower portion with a lateral eX- tension 22, the louter side of which is closed by aplate 23 rigidly secured thereto by means of bolts 24 or otherwise.

:Permanently connected with the housing 11 is `an air motor 25. This motor may be :JJ of any suitable character and as the motor in itself Aforms no part of the invention, -eX- cept as it enters into combination with other parts of the mechanism, it is unnecessary `to illustrate or describethe same in detail. nSufis a spur gear 30.

tice it to say that it is of the reversible rotary type and is provided with a controlling device or valve actuating lever 26. In the present instance, the motor is permanently attached to the plate 23 and I have interposed between the motor and the plate 23 a supplemetal casing 27 in which may be arranged such reducing gearing as may be necessary to reduce the speed of the motor to that required for theoperation of the jacl. The plate 23 has near its lower end a bearing 28 in which is journaled a shaft 29 carrying the beveled gear 21 and rigidly secured to this shaft between the beveled gear and the plate Meshing with this spur gear are two intermediate gears 3l which mesh with a pinion 3Q rigidly secured to a driving shaft 33 forming part of the motor mechansm, extending through the plate 23 and having its inner end journaled in a bearing 3dcar 1ied by the housing 11. Obviously the gear train between the shaft 33 and the beveled pinion 22 may take any suitable form but I use two intermediate gears for the purpose et dividing the load and thus relievingl the individual teeth of the several gears of a part of the load. It will be apparent that by the manipulation of the controlling device 26 the motor may be caused to rotate the screw 16 in a direction to impart either upward or downward movement to the lifting element. If the screw is of the low pitch type the motor will be operated in a reverse direction to drive the lifting element downward but where, as in the present instance, the screw is of the high pitch type the load will run down under its own weight and the jack will be self-lower- The permanent gear connection between the screw and the motor causes the latter to act as a. retarding device er compression brake to control the lowering of the load. Il the resistance offered by the motor to the downward movement of the load when the controlling device is in its neutral position is not suiiicient to properly retard the movement of the load, the controlling device may be manipulated to admit to the motor sutiicient air to provide the necessary retardation of the movement of the load. It will 50 be obvious that the amount of resistance which is necessary to properly control the load will depend upon the weight of the load and upon the pitch of the screw.

To prevent injury to the mechanism, which might result it the ram or lifting element were moved violently into Contact with the stops at either limit of its movement, I have provided means for automatically interrupting the operation of the motor when the lifting' element reaches the limit of its movement. In the present instance, I have arranged' within the housing ll, alongside of the lifting element, a vertical rod or shaft 35 which is here shown as journaled in bearings 36 and 37near the upper and lower ends of the housing. Rigidly secured to this shaft near its respective ends are cams 38 and 39 which arranged in the path of a part connected with ancL movable with the lifting eleuen'-, this part being here shown as a stud or pin i0 mounted i'n the flange 18 of the nut. The shaft 35 has rigidly secured thereto an Operating arm 4l which extends through the housing ll and is connected by a link 4t2 with an arm rigidly connected with the controlling device or valve actuating lever 2G. The connection between the shaft and the controliing device is such that when the arm fil is in an intermediate or neural position the controlling device for the valve actuating lever will be in an intermediate position and the valve which controls the admission ot air to the motor will be closed. lVhen the controlling device is actuated to admit air to the motor, to rotate the same in either direction, the shaft 35 will be rotated and the position ot the cams 38 and 39 shifted with relation to the pin Ll0 which is carried by the lifting element. rhe cams 38 and 39 are so arranged with relation to the pin that the contac; ot the pin with either cam will rotate the shaft hi a direction to move the controllingdevice 26 toits neutral position and thereby interrupt the operation of J:he motor.

TWhen a load is o be elevated the valve actuating device is manually operated in a direction to cause the motor to move the lifting element upwardly. This upward movement ot the lifting element continues, unless manually interrupted, until the stud ai) engages the cani 38, thus rotating the shaft 35 to close lhe valve and stop the motor. Inasmuch as the motor is stopped and the movement oi the lifting element interrupted while the stud is in engagementwith the cam the shaft will be held against return movement and the valve cannot be moved to a position to cause upward movement to be imparled to the lifting element until the stud has moved downwardly out of engagement with the cam. However, the valve actuating device is free to move to a position to cause downward movement to be imparted to lie lifting element. lVhen the lifting element reaches its lower position the stud 40 will actuate the cam 39 to stop the motor and the valve will be held against return movement until upward movement has been imparted to the lifting element. When the lifting element is moved from if's uppermost position or from its lowermost position tar enough to Carr.v7 the stud out of engagement with the cam the shaft 35 is free to rotae in either direction and the valve actuating device im be manually operated to stop the motor cause it to move the lifting element in en; direction.

Jacks of this type must, of course, be moved from place to place and as they are quite heavy` I have provided sDecial means her for transporting same. Ashere shown Ihave providedrthe jack. with Wheels 48 mounted on brackets 49 arranged beneath the motor. The arrangement of these wheels is such as when the jack is in an upright position the wheels will be out of contact with the ioor or other supporting surface, but when the ack is tilted the wheels will contact with thessupporting surface and the weight of the jack may be supported thereon while it is moved from place to place. The jaclris also provided with a handle44 by means of whichit may be tilted on to the wheels and moved from one place to another. In the present construction this handle is pivotally mounted'between lugs 45, which are secured to the housing near the upper end thereof, so that it can be moved either into an elevated or operative position, as shown in Fig. l, or into an inoperative position, in which it will lie close to the housing. The hub of the lever is provided with two peripheral recesses46 adapted to receive a spring pressed plunger or detent 47, which is slidably mounted in a recess in one of the lugs 45 and which serves to hold thek handle. in its adjusted position. The position of the detent 47 with relation to the hub of the'handle is such that the detent will project above the peripheral surface of the hub so that it may be engaged by the finger of the operatorand retracted to permit the movement of the handle fromone place to another. The detent serves to lock the handle rigidly in its adjusted position and when the handleis so locked in its elevatedposition it may bek grasped by the operator and the jack tilted rearwardly onto the wheels and balanced thereon so that it can be `easily moved from place to place.

While I have shown and'described one embodiment of my invention I'wish it to be understood that Ido not desire to be limited te the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a lifting jack, a standard, lifting mechanism carried by said standard and comprising a quick pitch screw adapted to permit the load to move downwardly under its own weight, an air motor mounted on said standard, having permanent geared connection with said screwA and serving both to rotate said screw in a direction to lift the load and as a retarding device to control the lowering of the load.

2. In a lifting jack, a hollow standard, a lifting element slidably mounted in said standard, a nut carried by said lifting element, a screw rotatably mounted in said standard and threaded through said nut, a beveled gear: rigidly secured to said screw, said standard havingv a lateral extension, a plate to close the outer endof said extension,

a bearing carried by said plate, a shaft'journaled in said bearing, a beveled gear secured to said shaft and meshing with the first mentioned gear, a spur gear rigidly secured to said shaft, an air motor permanently mounted on said plate and comprising a shaft extending through said plate, said standard having a bearing to receive the inner end of said shaft, and gears for connecting the last mentioned shaft with the first mentioned shaft.

8. In a lifting jack, a standard, lifting mechanism comprising a screw carried by said standard, an air motor rigidly secured to saidstandard and operatively connected with said screw, a valve tocontrol the opera-V ion of said motor, a cam movably supported by said standard, means for operatively connecting said cam with said valve, and a part movablevf'ith said lifting mechanism to engage said cam and impart movement to said valve.

4. In a lifting jack, a standard, a lifting element mounted in said standard, a screw for operating said lifting element, an air motor mounted on said standard, means for operatively connecting said air motor with said screw, a controlling device for said air motor, a shaft rotatably mounted on said standard, an operative connection between said shaft and said controlling device, a cam carried by said shaft, and a part carried by said lifting element and arranged to engage said cam and actuate said controlling device when said lifting element reaches the limitl of' its movement in one direction.

5. In a liftingjacl, a standart, lifting element mounted in said standard, a screw for operating said lifting element, an air motor mounted on said standard, means for operatively connecting' said air motor with aid screw, a controlling device for said air motor, a vertical shaft rotatably mounted within said standard, a cam rigidly secured to said shaft near each end thereof, a part carried by said lifting element and arranged to engage one of said cams when said lifting element approaches either limit of its movement and tc'impart rotatory movement to said shaft, and an operative connect-ion between said shaft and said controlling device.

6. In a lifting jack, a hollow standard, a lifting element mounted in said standard, a screw for operating said lifting` element, a motor permanently mounted onsaid standard, a gear train for permanently connecting said motor with said screw, a controlling device for said motor, a shaft mounted within said standard and extending lengthwise of said screw, means for operatively connecting said shaft with said cont-rolling device, and means controlled by the movement of said lifting element to impart rotatory movement to said'shaft in a. direction to move said controlling device to its neutral position when said lifting element reaches the end of its movement in either direction.

7. In a lifting jack, a standard, lifting mechanism carried by said standard, a motor mounted on said standard, and extending laterally therefrom, wheels mounted on said standard beneath said motor and arranged normally out of contact with the supporting surface, and the handle connected with said standard above said motor, whereby said jack may be tilted onto said wheelsv and moved from place to place.

Y 8. In a lifting jack comprising a standard, a lifting element carried by said standard and a motor mounted on said standard and operatively connected with said lifting element, a device to control the operation of said motor, a shaft rotatably mounted on said standard, means for operatively connecting said shaft with said controlling device, a cam connected with said shaft, and a part connected with said lifting element and arranged to engage said cam and actuate said controlling device to interrupt the operation of said motor when said lifting element is moved to a predetermined position.

9. In alifting jack comprising a standard, a lifting element carried by said standard and a motor mounted on said standard and operatively connected with said lifting element, a device to control the operation of said motor, a shaft rotatably mounted on said standard, means for operatively connecting said shaft with said controlling device, two cams connected with said shaft and spaced one from the other, and a part connected with said lifting element and arranged to engage one or the other of said cams and actuate said controlling device when said lifting element is moved to the limit of its movement in either direction.

10. In a lifting acl; comprising a standard, a lifting element carried by said standard and a motor mounted on said standard and operatively connected with said lifting element, a device to control the operation of said motor, a cam movably mounted near each end of said standard, means for operatively connecting said cams with said controlling device, and means connectedwith said lifting element to actuate one or the other of said cams when said lifting element is moved to the limit of its movement in either direction.

ll. In a lifting jack, comprising a standard, a lifting element carried by said standard and a motor mounted on said standard and operatively connected with said lifting element, a device to control the operation of said motor, shaft mounted within said standard and extending lengthwise thereof, means for one of said cams when said lifting element is moved .to the limit of its movement in one direction and to engage and operate the other of said ca ns when said lifting element is moved to the limit of its movement in the other direction.

l2. In a lifting jack, a standard, a lifting element carried by said standard, an air motor mounted on said standard, operating mechanism to connect said air motor with said lifting element, a valve to control the operation of said air motor, a device to actuate said valve, and means controlled by said operating mechanism to so control said valve actuating device that said valve inay remain in its open position during the travel of said lifting element and will be closed when said lifting element reaches the limit of its movement.

i3. In a lifting jack, a standard, a lifting element carried by said standard, an air motor mounted on said standard, operating mechanism to connectsaid air motor with said lifting element, a valve to control the operation of said air motor, a device to actuate said valve, and means controlled by said operating mechanism to so control said valve actuating device that said valve may remain in its open 1position when said lifting element is in an intermediate position and will be closed when said lifting element is moved to the lini it of its movement in either direction.

14. In a lifting jack, a standard, lifting element carried by said standard, an air motor-mounted on said standard, operating mechanism to connect said air motor with said lifting element, a valve to controlthe operation of said air motor, a shaft journaled on said standard and extending lengthwise of said lifting element, means for operatively connecting said shaft with said valve, and means actuated in accordance with the movement of said lifting element to impart rotatory movement to said shaft and close said valve when said lifting element is moved to the limit of its movement.

l5. In a lifting jack, a standard, a lifting element carried by said standard', an air motor mounted on said standard, operating mechanism to connect said air motor with said lifting element, a valve to control the operation of said air motor, and a device to actuate said valve, said lifting element having a part to engage said valve actuating device and close said valve as said lifting element nears the limit of its movement in one direction.

16. In a lifting jack, a standard, a lift-ing element carried by said standard, operating mechanism to actuate said lifting element, an air motor to drive said operating mechanism, manually operable valve mechanism to control the operation of said air motor, said valve mechanism being movable in either direction from its closed position to control the direction in which said lifting element is moved by said motor, and means actuated in accordance With the movement of said lifting element to move said valve mechanism to its closed position when said lifting element reaches the limit of its movement in one direction, said means being arranged to prevent the return of said valve mechanism to the position from which it has been moved until said lifting element has been moved in the opposite direction and to permit said valve mechanism to be manually moved in a direction to reverse the operation of said motor.

17. In lifting jack, a standard, alifting element carriedby said standard, operating mechanism to actuate said lifting element, an air motor to drive said operating mechanism, manually operable valve mechanism to control the operation of said air motor, said valve mechanism being movable in either direction from its closed position to control the direction in Which said lifting element is moved by said motor, an automatically operated device for operating said valve mechanism, and means actuated in accordance with the movement of said lifting element to cause said operating device to move said valve mechanism to its closed position when said lifting element reaches the limit of movement in either direction and to permit the further movement of said valve mechanism in the same direction to reverse the operation of said motor.

18. In a lifting jack, a standard, a lifting element carried by said standard, operating mechanism to actuate said lifting element, an air motor to drive said operating mechanism, a valve to control the operation of said motor, said valve having a neutral position and tivo operative positions, manually operable means to actuate said valve, an automatically operated device to actuate said valve, and means actuated in accordance With the movement of said lifting element to cause said automatically operable device to move said valve from one operative position to said neutral position when said lifting element reaches the limit of its movement in one direction, said automatically operable device being so arranged that it Will prevent the return of said valve to said operative position but Will permit the same to be manually moved to its other operative position.

19. In a lifting jack, a standard, a lifting element carried by said standard, operating mechanism for said lifting element, an air motor to actuate said operating mechanism, a valve to control said motor, a rock shaft extending lengthwise of said standard, means for operatively connecting said rock shaft With said valve, a laterally extending part secured to said rock shaft, and a part movable in accordance with the movement of said lifting element and arranged to engage the first mentioned part and impart operative hereto.

ION V. K. HOTT. 

